US2730784A

US2730784A - Paving dowel supporting construction

Info

Publication number: US2730784A
Application number: US377373A
Authority: US
Inventors: Thomas C Salisbury
Original assignee: P B A Co
Current assignee: P B A Co
Priority date: 1953-08-31
Filing date: 1953-08-31
Publication date: 1956-01-17
Anticipated expiration: 1973-01-17

Description

United States Patent O PAVING DOWEL SUPPORTING CONSTRUCTION Thomas C. Salisbury, San Dimas, Calif., assigner, by mesne assignments, to P. B. A. Company, Alhambra, Calif., a corporation of California Application August 31, 1953, Serial No. 377,373

1 Claim. (Cl. 25--118) This invention relates to a paving dowel supporting construction and, more particularly, to a paving dowel supporting construction which includes a paving header for defining the lateral edge of a roadway or other concrete construction and a keyway channel, said channel being provided with means for supportinga plurality of paving dowels in predetermined relationship with one another and a prepared surface upon which concrete is to be poured.

it is conventional practice, at the present time, in laying concrete roadways, airstrips, and other analogous structures to utilize reinforcing dowels which are constituted by a stud member which is threaded at one end, said stud member being mounted in a conventional keyway channel on a paving header and being threaded at its outer end to receive a mating nut. After the concrete has been poured and the paving iron and keyway channel removed, an additional paving dowel having a threaded end is screwed into the mating nut. Recent advances in the cost of raw steel stock and the cost of fabricating the same have led to greatly increased costs in the fabricating of `the aforementioned conventional dowel structures and efforts have been made to utilize paving dowels constituted by elongated bars, one end of each of which is inserted in the paving concrete during the pouring thereof, While the other end thereof is bent at a right angle, said bent right-angle portion being mounted within a conventional keyway channel to support the same. t t

However, serious difficulties have arisen because of the utilization of such conventional constructions in supporting the right-angularly bent paving dowels, among them being the fact that when such right-angularly bent pav ing dowels have been installed with the right-angularly bent legs thereof within a conventional channel, it is necessary to straighten them to remove the channel and it is then frequently necessary to once again bend them to permit the passage of road-building equipment Without the danger of breaking olf or destroying the extending ends of the paving dowels. Repeated bending of the paving dowels causes crystallization at the `bend points of the dowels `and frequently results in the breakage thereof. t

Furthermore, it is necessary to permit the concrete to cure for a predetermined time before the channel can be removed by straightening the right-angularly bent legs of the dowels to permit such removal. t t

lt is, therefore, an object of my invention to provide a paving dowel support construction which includes a conventional paving header having mounted thereupon a keyway channel which includes an intermediate form face or wall, said form wall being provided with a recess in the face thereof which is designed to receive the rightangularly bent legs of a plurality of paving dowels. The manifest advantages of the supporting construction of my invention include the fact that it is not necessary to subject the paving dowels to repeated bending since, when the paving dowels have their right-angularly bent legs y 2,730,784 Patented Jan.. l?, 1956 ICC disposed in predetermined relationship within the recess in the face of the form wall of the channel and the concrete has been poured to embed the extending legs thereof in said concrete, the paving header and its associated keyway channel can be readily removed from operative relation with the concrete after a relatively short period of time due to the fact that the right-angularly bent legs of the paving dowels do not have to be bent to release the keyway channel from operative engagement therewith.

Another object of my invention is the provision of a paving dowel supporting structure in which the recess in the face of the keyway channel is constituted by an elongated groove into which the right-angularly bent legs of the paving dowel are inserted to maintain said paving dowels in spaced relation with one another and with a previously prepared surface upon which concrete is to be poured.

An additional object of my invention is: the provision of a paving dowel supporting structure which includes fastening means for maintaining the right-angularly bent legs of the paving dowels in operative relationship with the aforementioned recess in the face of the keyway channel to prevent dislocation of said right-angularly bent legs from operative engagement with said recess.

An additional object of my invention is the provision, in a paving dowel supporting structure of the aforementioned character of fastening means constituted by spring clips whose opposite ends are insertable in. openings provided in the face of the keyway channel, said spring clips being designed to restrain the right-angularly bent legs of the paving dowels against inadvertent dislocation from the recess in the face of the keyway channel.

The utilization of spring clips is advantageous in that it permits the lzeyway channel to be readily removed from operative engagement with the right-angularly bent legs of the paving dowels by merely prying the keyway channel outwardly out of engagement with the keyway formed in the edge of the concrete structure, thus readily releasing the keyway from operative engagement with the right-angulariy bent legs and completely eliminating the necessity for bending and re-bending said legs.

An additional object of my invention is the provision of a dowel supporting structure of the aforementioned character which includes an elongated recess for the reception of the right-angularly bent legs of the paving dowels, said elongated recess being constituted by a continuous groove whose longitudinal axis is parallel to the longitudinal axis of said channel, said groove having a configuration which permits it to conform substantially to the external configuration of the right-singularly bent legs of said paving dowels and having a depth which permits the entire cross-sectional area of the paving dowels to be received in the recess.

@ther objects and advantages of my invention will be apparent from the following specification and the accompanying drawing which is for the purpose of illustration only and in which:

l is an isometric View showing a dowel support construction of my invention in operative relationship with apaving dowel and with the adjacent edge of a concrete structure defined by said paving dowel supporting construction;

Fig. 2 is a top plan view taken in the direction of the broken line 2f2 of Fig. l;

Fig. 3 is a vertical, sectional view taken on the broken line 3-3 of Fig. 2; and

Fig. 4 is a vertical, sectional view taken from the broken line 4--4 of Fig. 2.

Referring to the drawing, and particularly to Figs. l and 2 thereof, l show a paving dowel support construction in manufactured in accordance with the teachings of my invention and including a conventional paving header "or-iron 11,`said paving header including a base portion 13 which is conventionally pegged or otherwise aiiixed toa surface ,1.4 upon whiclra concrete structure such as a roadway-is to be'laid.

'Formed integrally with the base 13 of the paving header 11 isa vertical form wall 15, lsaidiform wall .being adapted to define. the lateraledge 17 yofa concrete roadway 122er other concrete structure. 'Formed integrally with the upper edge of the verticalforrn wall of ,the paving headerV 11 is a tread or track 19,upon which the wheels Qfroad-laying equipment can ride during therprocess of layingtheconcrete roadbed 13. Itwillbe noted that the pavllg header 11 is constituted from a single piece of relatively heavyY gage sheet steel stock and that the base 13, the vertical form wall .15, andthe tread or track 19 are integrally formed with one another.

it should also be noted that Fig. 1 of the drawing shows two .headers 1 1 with theirA endsdisposed in abutting relationship with each other and that, therefore, two dowel supporting structures 10.are also shown.

The paving header` 11 has .mounted upon the vertical form wall 15 thereof `a keywaylchannel 22, `said keyway channel including an intermediate form wall 23 which is disposed v,in spaced relation with the face4 of the vertical form wall of the paving header 11 by means of angularly oriented, instruckspacer walls26 yand 27 formed integrally therewith. The VVkeyway ychannel 22 is utilized to v,form the longitudinal `keyway 25 in the lateral edge of the concrete structure or roadway 18 so that an interlocking joint will be provided with an adjacent roadway section.

In order toreinforce the .roadway18, a plurality of paving dowels is lutilized which are embedded in the concrete during the pouring thereof. The paving dowels 30 are constituted by right-angularlyy bent steel bars 31 of substantially cylindrical crosssectionalconfiguration and are right-angularly bent to provide right-angularly bent positioning legs 33 which provide support for normally extending legs 35, said normally extending legs 35 terminating in ground engaging legs 37 `which support them in spaced relation with the surface 14upon which concrete is to be poured.

A longitudinally extending, elongatedl dowel receiving and supporting recess 40 is provided in the intermediate form wall 23 of each of the keyway channels 22, said elongated recess being designed to yreceive the right-angularly bent legs 33 of the dowels 30 tol support said dowels in spaced relation with one another and to maintain them in predetermined orientation with the surface 14 during the concrete laying process. The elongated recess 4t) in each of the keyway channels 22 is constituted by an elongated groove 41, said groove 41, as best shown in` Figs. 3 and 4 of the drawing, being of substantially arcuate cross-sectional configuration to permit it to conform to the peripheral configuration of the right-angularly bent legs 33 of the paving dowel located therein.

It should be noted at this juncture that, in addition to the mating configuration of theelongated groove 41 with the peripheral configuration of the right-angularly bent legs 33 of the paving dowel 30, the depth of the groove 41 is suicient to permit the entire cross-sectional dimension of the right-angularly bent legs 33 of the associated paving dowels 30 to be received therein so that no portion thereof protrudes beyond the face of the intermediate form wall 23 of the keyway channel 22. ln addition, the width of the groove 41, as indicated by the line A in Fig. 4 of the drawing, is slightly greater than the cross-sectional width of the right-angularly bent legs 33 of the associated paving dowels 3l) so that the right-angularly bent legs 33 can be readily received in the groove 41.

Inlorder tomaintainthepaving ldowels 30 in l,operative relation with V the vgrooves 41 inthe intermediate form walls 23 of the keyway channels 22, fastening means 46 are provided, said'fastening means being constituted in one instance, as best shown in Fig. 3 of the drawing, by tie wires 47, the free ends of which are inserted through openings 49 in the intermediate form wall 23 of the keyway channel 22 and tied in a knot 51 to restrain the right-angularly bentllegs 33 of the paving dowels 3,0 from dislocation `from the ,elongated kgroove 41 in said keyway channel.

An alternative typeof fastening means isy provided, as best lshown in Fig. 4 ofthe drawing, bya .spring clip 55 which may be formed from either'` spring sheet or'spring wire stock and which has its `opposite ends .insertable through the aforesaid openings"49 in the intermediate form wall 23 of thekeywaychannellZZ Vto maintain the right-angularly bent legs 33 of the paving dowels 30 in operative engagement with the groove 41.

In order to maintain the keyway channel 22 `in operative relationship with the yheader '11, `mounting means 60 .is provdeisad regulating,,means,beinensfiitedy U-shaped mounting'brackts 6 whoseends'are welded to the inner wall of thefgrooveiil asbest shown inligs. 2 and 4 ofthe drawing. u l Y' The U-shaped mounting bracketsrl are receivable` in andy extend through longitudinally spaced'openingsf provided in the vertical form wallA 15 ofthe paving header 11, as best shown inFig. 4 `of ,the drawing, andare engaged by spring clips -65, said springfclipspreventing the inadvertent separation of theV =keyway channel l2'2 f rorn the paving header 11.

The manner in which the paving dowelsupporting construction of my invention may beutilized is asfollows: The right-angularly bent legs 33 of 4thepaving `dowels 30 areV first, disposed in operative engagement therecessesV 40 in thepintermediate forni Jwalls of i the` keyway channels 22 and are restiainedV Afromdislocation ,therefrom by the utilization of v'fastening means "'46, such las the tie wires 47 or the spring clips 55`whichare inserted through the openings49 in the intermediate form' wall 23 and, in the case,. of thetiewiresk47,knotteldbaslatl. The U-shaped mountingbrack'etsllwfare then inserted through the longitudinally spaced openingsf63 inthe verticalk form wall 15 ofthe paving headerlilV andthe spring clips ,65 are thenlinserted through'zthe Jlil-shaped mounting brackets 61 to inaintain'thel elongatedkeyway channels 22 in predetermined relationship upon the` verti` cal form wall 15 of the paving header` 11. fl'lie paving headers 11 are then pegged to a prepared s urfacelllfandlthe concrete roadway 18 is poured.

After a relatively short curing period, the pavingV headers 11 arel disengaged yfrom y operative .'rlationshipwith the keyway channels 22 by're'movingthev lspring clips 65 from the lU-shaped mounting brackets 61 ,and laterally displacing the pavingheaders, 11fto'fcaluvse,,the nidunting brackets 61 to pass through the" penings. 63in, the vertical form walls 15 of the paving *heade-r's''11. If ftis'aw'iresA 47 are utilized as fastening ineansi', they arefthen clipped andthe ,elongatedv keyway`- channelsZZprield outA of lthe keyways 25 formed 'thereby in'thelate'al edge'17 of the concrete roadway 18. If spring clips 55 are utilizedgitis merely necessary to pry the elongated keyway ychannels 22 out of engagement with the keyway 25, v thus releasing the keyway channels I22, from `operative engagementvwith the right-angularly bent legsy 33 fof the paving fdowelsf 30 without the necessity forbending the paving Vdowels-,prior to such release.

This is a manifest advantage over the priorkart Asince a relatively short curing time is necessary to permitvthe paving header 11 landthe :keyway channels `22 to be removed from operative engagement ,yviththe, vlateral edge 17 of the concrete roadway y 18Jifithereis none` fity for bending the right-angularly bent-legs; 33. of thedfp ying dowels 30. l

Furthermore, there. is a great savingin timeandlabor since it is, not necessary -to bend the.'rightangularlynbent legs 33 of the paving dowels 30 outwardly to free the keyway channel from operative engagement with the lateral edge 17 of the roadway 18, nor is it necessary subsequently to rebend the right-angularly bent legs 33 of the paving dowels 30 into their originally bent position to prevent the destruction thereof by roadworking equipment. In addition, the crystallization of the dowels and the breakage thereof encountered because of continual and repeated bending of the right-angularly bent legs 33 thereof is eliminated since it is only necessary to bend the right-angularly bent legs 33 thereof outwardly when the adjoining concrete strip is to be poured.

It should be noted, as best shown in Fig. l of the drawing, that a right-angularly bent leg 33 of a paving dowel 30 can be inserted in the contiguous recesses 40 of adjacent elongated keyway channels 22, thus serving as a mating member to accurately align the keyway channels 22 and the associated paving headers 11.

I thus provide by my invention a paving dowel supporting construction which is characterized by extreme ease of assembling the dowels in supporting relationship therewith and which is also characterized by the ease of disassembly thereof from operative relationship with said dowels. Furthermore, the breakage of dowels incident to the use of conventional dowel supporting constructions is eliminated and, due to the fact that the paving dowel supporting construction of my invention can be dismantled from operative relationship with a poured roadway or other concrete construction after a relatively short period of time, there is no necessity to provide a large number of paving dowel support constructions since the paving dowel support constructions of my invention can be utilized repeatedly during the same job because of the relatively short curing time necessary before the dowel support construction of my invention is removed from operative relation with a concrete structure which has been poured by by the use thereof.

The keyway channel 22 can also be used to support reinforcing dowels in a vertical plane, as at the edge of a tilt-up panel. To accomplish this desired end, the keyway channel 22 is supported at the ends of, for example, a tilt-up form with the dowels having their free ends extending into the concrete as it is poured. Subsequently, when the panel is erected, the dowels can be bent outwardly to free the keyway channel from the panel.

I claim as my invention:

In a dowel supporting construction :for supporting a plurality of paving dowels in predetermined, spaced relation and for defining the edge of a concrete structure in which portions of said dowels are embedded, the combination of a paving header, said header including a base and a vertical form wall on said base, said form wall having a plurality of longitudinally spaced fastener receiving openings therein; an elongated keyway channel removably secured to said form wall intermediate the upper and lower edges thereof, said keyway channel having a vertical, intermediate wall disposed in spaced relation with said form wall, said intermediate wall having a continuous groove provided in the face thereof defined by a rearwardly extending, continuous protrusion in said intermediate wall for the reception of a plurality of dowels; said groove being of arcuate cross section at the bottom thereof to prevent seepage of concrete between the dowels and the bottom of the groove and the diameter of said groove being substantially the same as the diameter of said dowels; and fastener means extending through said openings in said form wall for demountably maintaining said channel thereupon.

References Cited in the ile of this patent UNITED STATES PATENTS 1,948,213 Heltzel Feb. 20, 1934 2,489,851 Bean Nov. 29, 1949 2,618,038 Stewart Nov. 18, 1952